Cardiac catheterization is an invasive procedure which exposes each patient undergoing the procedure and the vasculature of that patient to potential contamination, making sterility a high priority. Because of the risks of cross-contamination, most items used during the catheterization procedure are disposable. Indeed, certain items which it would be desirable to preserve are disposed of in the interest of maintaining patient-to-patient sterility.
For example, non-ionic contrast media or dyes used in a cardiac catheterization procedure are relatively expensive fluids, with costs typically exceeding $1.00 per milliliter (ml). In the current cath lab environment, non-ionic dye media is supplied to the lab in 150 ml containers which is, for the material provided, a standard container. However, a typical catheterization procedure uses anywhere from 80 to 120 mls. At the end of such procedure, the container of non-ionic contrast media is discarded and 30 to 70 mls of contrast media is also discarded with that container, resulting in a loss of 20 to 47 percent of the contents of that container.
In a major cath lab setting where dozens of such procedures are performed every day, the use of non-ionic contrast media over a years time can amount to upwards of one million milliliters of fluid. Thus, an apparatus which could preserve the sterility and integrity of the non-ionic contrast media stored in the container and eliminate waste could produce significant savings in a cath lab. The foregoing example would envision annual savings of $200,000 to $470,000 in a single significant cath lab situation.
Of course, simply saving non-ionic contrast media is not enough. The associated apparatus must maintain the sterile barrier between fluid container and patient and maintain that sterile barrier from patient to patient as well.
Accordingly, the present invention envisions apparatus wherein the primary dye source, or primary non-ionic contrast media container, is connected to a secondary dye source such as a metered burette, with sufficient safeguards including at least one one-way check valve and at least one stop cock between the primary dye source and the secondary dye source to assure that a sterile barrier exists between the primary dye source and the secondary dye source, so that fluid can be transferred from the primary dye source in an amount sufficient to perform a cardiac catheterization procedure.
Typically, the minimum amount of non-ionic contrast media required to perform a single cardiac catheterization procedure is in the range of 80 to 120 mls. Accordingly, the one-way check valve between the primary dye source and the secondary dye source permits 80 to 120 mls. of non-ionic contrast media to be released into the secondary dye source when the stop cock therebetween is opened. When the transfer of fluid between the primary fluid source and the secondary fluid source is complete, the stop cock is closed to cut of f the fluid transfer and to support the maintenance of a sterile barrier between the primary dye source and the secondary dye source. Should additional fluid be required during the procedure, the stop cock can be reopened to release through the one-way check valve an amount of fluid sufficient to complete the procedure while still maintaining the sterile barrier between the primary dye source and the secondary dye source.
During the cardiac catheterization procedure, fluid flow is from the secondary dye source through a fluid line connected by a catheter to the patient. Before the contrast fluid media is transferred from the secondary dye source to the patient, air bubbles in the contrast media are removed by returning aerated fluid in the line to the secondary dye source and venting the bubbles through a vent-to-air member provided in the secondary dye source, thereby preventing air bubbles from being introduced into the blood stream of the patient. The vent-to-air member prevents a partial vacuum in this retrograde movement application. The vent also discharges air entrapped in the fluid to the atmosphere, as well as replaces fluid with air as such fluid is transferred from the secondary fluid source to the patient.
Further, a sterile barrier is maintained during the cardiac catheterization procedure between the primary dye source and the secondary dye source by the one-way check valve therebetween and, on completion of the catheterization procedure, the secondary dye source can be disconnected from the primary dye source enabling the primary dye source to be connected to a next secondary dye source associated with a second procedure and a second patient.
In an alternate embodiment a pair of vented spikes may each be connected to a primary dye source with proper coupling means connecting the output of each of two primary dye sources to a single connector and then into a single secondary dye source.
The proposed apparatus as described herein eliminates the substantial waste of a relatively expensive non-ionic contrast media, but yet maintains a sterile barrier between primary and secondary dye sources so as to preserve the integrity and the sterility of the catheterization procedure for each patient undergoing the procedure. Further, the apparatus of the present invention enables the development and use of primary fluid source containers of various sizes and configurations to improve the versatility and the convenience of such containers, as well as to further minimize waste in the catheterization procedure.